cmake: Set min version required, fix some warnings, remove network/error.c from src/CMakeLists.txt.

extras/buildsystem/cmake/CMakeLists/root_CMakeLists.txt

 PROJECT(vlc)
 
-CMAKE_POLICY(VERSION 2.5)
+cmake_policy(VERSION 2.6)
+cmake_minimum_required(VERSION 2.6)
 
 ENABLE_TESTING()
 

extras/buildsystem/cmake/CMakeLists/src_CMakeLists.txt

 
 add_definitions(-Dasm=__asm__ -D_INTL_REDIRECT_MACROS)
-add_definitions(-DLOCALEDIR=\\"${CMAKE_INSTALL_PREFIX}/locale\\")
-add_definitions(-DPLUGIN_PATH=\\"${CMAKE_INSTALL_PREFIX}/lib/vlc\\")
-add_definitions(-DDATA_PATH=\\"${CMAKE_INSTALL_PREFIX}/share/vlc\\")
+add_definitions(-DLOCALEDIR="${CMAKE_INSTALL_PREFIX}/locale")
+add_definitions(-DPLUGIN_PATH="${CMAKE_INSTALL_PREFIX}/lib/vlc")
+add_definitions(-DDATA_PATH="${CMAKE_INSTALL_PREFIX}/share/vlc")
 
 # vlc
 add_executable(vlc vlc.c)
@@ -76,7 +76,6 @@ set( SOURCES_libvlc_common
     network/acl.c
     network/getaddrinfo.c
     network/io.c
-    network/error.c
     network/tcp.c
     network/udp.c
     network/httpd.c